Future Research Questions: As an independent investigator, I will focus on answering two important questions: 1) What are the cells-of-origin or epigenetic programs that produce the two major types of lung tumors? and 2) How can epigenetic therapies be incorporated into useful cancer therapeutics? Background Lung cancer remains the leading cause of cancer related deaths world-wide. Precision medicine options for lung cancer patients may help to decrease the mortality of the disease by targeting the most vulnerable pathways in each specific cancer. However, these efforts are complicated by both the genetic and epigenetic complexity of lung tumors. How epigenetic programs influence critical aspects of lung tumorigenesis and normal lung biology remains an uncharted area. Furthermore, the lineage relationship and epigenetic differences between the two major subtypes of non-small cell lung cancer, namely lung adenocarcinoma and lung squamous cell carcinoma, are unclear. My main goal is to find methods to incorporate epigenetic drugs into effective cancer therapies. I will initially focus on lung stem cell biology as my platform to elucidate the cellular origins and epigenetic therapeutic vulnerabilities in lung cancer. Methodology The research proposed herein will allow for direct comparison of the transformation capacity of several lung stem/progenitor cell pools through FACS isolation, lentiviral genetic modulation and 3D organotypic culture. The transformation potential and subtype acquisition of the cell pools will be tested by injection into the lungs of immunocompromised mice. This novel system will allow for careful dissection of what lung cells can serve as tumor cells-of-origin and in what contexts (i.e. genetic mutations and epigenetic modulation). These results can be linked back to the most permissible epigenetic states for transformation, and allow understanding of how epigenetic programs are co-opted by tumor cells during malignant transformation. In parallel, I will study the effects of different epigeneti therapeutics, namely inhibition of BRD4, EZH2 or G9A, on genetically defined murine lung tumors. I will again use the 3D organotypic culture assay, which I have optimized for primary tumor cell growth. This approach will allow cost-effective but biologically relevant assessment of the effects of epigenetic therapies on varied subtypes and genotypes of lung cancer. Both of these approaches will be translated to human biology by using human cells in the 3D cultures. Career Potential I have had a very successful post-doctoral career in the laboratory of Carla Kim at Boston Children's Hospital, and I have established a strong relationship with my collaborators for this award, Drs. Leonard Zon and Kwok- Kin Wong. I have an outstanding environment and a comprehensive plan that will allow me to transition to an independent research role. My ultimate goal is to lead a research group exploring the relationships between stem cells and cancer, with a specific focus on novel cancer therapeutics. I know that the K22 award would greatly aid me in realizing these goals.